The present invention relates to a device for performing different work tasks within a work area, in particular a ski run area, comprising a working unit, a manoeuvring means to which the working unit is attached, and that the manoeuvring means is intended to be arranged to a vehicle.
For ski resorts, special vehicles are used in preparing the foundation for the ski runs and the cross-country trails. These special vehicles, so called snowgrooming vehicles, are track-driven in order to be able to manoeuvre. They are equipped with snow forming devices that are pulled behind for smoothing the surface. Further they are arranged with hydraulically manoeuvred ploughs in the front for transporting snow, such as to cut off bumps and fill deeper tracks and cavities.
During recent years the demands on a more varied skiing in the ski runs has increased, in particular with the arrival of snowboard and its utilisers, but also for ordinary skiing. For that the ski run areas have been designed with different xe2x80x9cartificialxe2x80x9d configurations, such as mogules, jumps and so called half-pipes. The latter is mainly U-shaped runs where the riders go up and down on the sides and perform different tricks and stunts. These designs demand relatively large amount of work to build up and maintain, for which the conventional snowgrooming vehicles are not optimally designed. In particular the build-up of high jumps and half-pipes where the height from its bottom to the edge can be several meters, require moving large amounts of snow up to heights that the conventional snowgrooming vehicles can not accomplish. Previously, this has required manual labour or the use of digging vehicles that are not adapted to be driven on snow.
One attempt to accomplish half-pipes and the like curved tracks is described in WO9833986, showing a snow vehicle on which a crane arm is attached, which partly is rotatable around a vertical axis and partly has a joint. At the end of the arm, a snow working unit is arranged, which comprises a rotating snow mill roll or mat. During use, the machine is driven along the longitudinal direction of the track and the snow working unit is moved along the curvature of the track for forming the same.
The device according to WO9833986 displays a number of drawbacks. Because the device is attached to the snow vehicle, the usage of the vehicle is limited, i e the vehicle becomes more or less a special vehicle for only preparing half-pipes and the like tracks and surfaces. In order to fully use the vehicle for other work tasks that are present at ski run areas, the device has to be dismantled, which is time-consuming.
A further drawback is that the device is mounted behind the driver""s cab in the driving direction of the vehicle, which essentially decreases the preparation work of the driver in that the driver, after completing the preparation of a section of the track, has to turn around in order to drive to the next section, and then again turn backwards.
A further drawback is that the snow working unit that is disclosed in the description is not capable of transporting any larger amounts of snow, instead it is only capable of finely adjusting a previously coarsely formed track. This implies that the coarse-forming has to be performed by another machine or by hand in as conventional manner. With the working unit described, there are further large problems in directing and controlling the snow that has been worked away in that there are no means present for directing the snow, but rather it is thrown away more or less uncontrolled, which makes it difficult for the driver to direct the snow to parts that need to be built up. Further there is a great risk that the milled snow creates a xe2x80x9csnow cloudxe2x80x9d of fine particles, deteriorating the sight, whereby the drive has difficulties controlling the way the unit is steered.
As regards the design of half-pipes, demands are put, especially for competitions, regarding dimensions and the rounding of the walls as well as the surface of the foundation and durability. These demands have led to labour-intensive, and therefore costly, operations.
Apart from the above mentioned aspects, it shall be noted that a plurality of work tasks needs to be performed on a ski run area, such as general snow handling, control of ski lifts, whereby the workers need to reach certain heights, removal of grass and bushes during summer time, the laying of water pipes for snow guns, removal of trees and the like. A work area such as a ski run area thus has a need for a device, which in a flexible and simple way can fulfil these requirements without departing from functionality and without requiring several different work machines.
The aim of the present invention is to provide a device for the performing of different work tasks that remedies the above problems, that preferably can be attached to and utilised by machines present in ski run areas, that is efficient and flexible and adapted to be used for many work tasks present in a ski run area during winter as well as summer.
This aim is obtained according to one aspect of the invention with a device according to patent claim 1.
Preferable embodiments of the invention are characterised by the dependent claims.
The device according to the invention comprises an arm rotatably arranged to a stand and that the arm is jointed. The arm is further also slidable in the longitudinal direction for altering the length of the arm. At the end of the arm, a number of different work tools can be attached, such as for example a thrower for removing and forming larger amounts of snow, a preparation device for fine preparation, shovel, work platform, bush cutter, gripping means, and other tools. The stand is designed as an individual unit that can be releasably attached to a vehicle.
This makes it very simple to attach and detach the device according to need, which provides a very flexible way of working and which for example provides for a snowgrooming vehicle, which is used in ski run areas for preparing the ski runs, to readily attach the device in order to perform machining and preparations of half-pipes and the like. Due to the design of the arm with its joint and the moving in and out of the outreach, advantages are obtained in that a very good control of the working unit can be achieved regarding the desired forms, radii and the like and in that the working area can be varied from very small protrusions to the really large half-pipes with wall heights of up to 6 meters.
The device according to the invention utilises according to one embodiment a snow thrower specially adapted for the working and forming of snow surfaces such as half-pipes. This comprises a rotor with teeth designed and arranged such that a very good working is obtained also on very hard packed snow and where the worked snow can be controlled partly for obtaining an even worked surface, partly for removing and placing of the snow to selected places and partly for avoiding the xe2x80x9csnow cloudxe2x80x9d that often tends to form during milling of the snow, whereby the driver has full visibility of the working unit.
According to a further aspect of the invention, it is characterised by a snow working unit comprising a milling device for the grinding of the snow surface and packing part following in the work direction of the snow working unit comprising a substantially planar surface.
The advantages with the device according to the present invention are several. Because the working unit is maneouvrable in at least three degrees of freedom, a very flexible device is obtained with a large work area. Due to the jointed arm arrangement movable along three coordinate axes, complex forms, such as for example the sides of a half-pipe, can be created in a labour saving and at the same time exact way. When further the snow working unit is jointly, and also rotatably, arranged to the device, a very exact steering is obtained for optimal result.
Because the direction of the worked snow, and thrown from the snow working unit, can be controlled to the desired location, a labour-saving way of handling the snow is obtained rather than if it is thrown away in arbitrary directions.
With the preferred snow working unit, a very even but yet durable surface is obtained in that the milling unit due to the xe2x80x9croughingxe2x80x9d of the surface firstly ensures that cold air penetrates the snow surface, whereby the thickness of the harder surface layer increases. The subsequent vibrating packing provides an even higher hardness and wear-resistance to the harder surface layer. The final adjustment then provides an even running surface.
These and other aspects of, and advantages with, the present invention will become apparent from the following detailed description of some embodiments of the present invention and from the accompanying drawings.